diff --git a/ETL/trunk/ETL/_handle.h b/ETL/trunk/ETL/_handle.h
index 3f07503..ae534d5 100644
--- a/ETL/trunk/ETL/_handle.h
+++ b/ETL/trunk/ETL/_handle.h
@@ -32,7 +32,13 @@
 
 /* === H E A D E R S ======================================================= */
 
+// include the next line in an attempt to increase stability
+#define ETL_LOCK_REFCOUNTS
+
 #include <cassert>
+#ifdef ETL_LOCK_REFCOUNTS
+#include <glibmm/thread.h>
+#endif
 
 /* === M A C R O S ========================================================= */
 
@@ -67,6 +73,9 @@ class shared_object
 {
 private:
 	mutable int refcount;
+#ifdef ETL_LOCK_REFCOUNTS
+	mutable Glib::Mutex mutex;
+#endif
 
 protected:
 	shared_object():refcount(0) { }
@@ -79,11 +88,19 @@ protected:
 
 public:
 	void ref()const
-		{ assert(refcount>=0); refcount++; }
+	{
+#ifdef ETL_LOCK_REFCOUNTS
+		Glib::Mutex::Lock lock(mutex);
+#endif
+		assert(refcount>=0); refcount++;
+	}
 
 	//! Returns \c false if object needs to be deleted
 	bool unref()const
 	{
+#ifdef ETL_LOCK_REFCOUNTS
+		Glib::Mutex::Lock lock(mutex);
+#endif
 		assert(refcount>0);
 
 		refcount--;
@@ -91,6 +108,9 @@ public:
 		if(refcount==0) {
 #ifdef ETL_SELF_DELETING_SHARED_OBJECT
 			refcount=-666;
+#ifdef ETL_LOCK_REFCOUNTS
+			lock.release();
+#endif
 			delete this;
 #endif
 			return false;
@@ -100,7 +120,12 @@ public:
 	}
 
 	int count()const
-		{ return refcount; }
+	{ 
+#ifdef ETL_LOCK_REFCOUNTS
+		Glib::Mutex::Lock lock(mutex);
+#endif
+		return refcount;
+	}
 }; // END of class shared_object
 
 // ========================================================================
diff --git a/synfig-core/trunk/configure.ac b/synfig-core/trunk/configure.ac
index b972337..392443b 100644
--- a/synfig-core/trunk/configure.ac
+++ b/synfig-core/trunk/configure.ac
@@ -365,6 +365,10 @@ dnl	])
 ])
 CONFIG_DEPS="$CONFIG_DEPS sigc++-2.0"
 
+PKG_CHECK_MODULES(GTHREAD, [gthread-2.0],,[
+	AC_MSG_ERROR([ ** Required library gthread-2.0 not found.  (See package 'libglib2.0-dev'?)])
+])
+
 dnl PKG_CHECK_MODULES(GLIB, glib-2.0,[GLIB="yes"],[GLIB="no"])
 
 
diff --git a/synfig-core/trunk/src/tool/Makefile.am b/synfig-core/trunk/src/tool/Makefile.am
index f019d0b..5eec1dc 100644
--- a/synfig-core/trunk/src/tool/Makefile.am
+++ b/synfig-core/trunk/src/tool/Makefile.am
@@ -8,7 +8,7 @@ INCLUDES=-I$(top_builddir) -I$(top_srcdir)/src
 bin_PROGRAMS	=	synfig
 
 synfig_SOURCES = main.cpp
-synfig_LDADD = ../synfig/libsynfig.la @SYNFIG_LIBS@ @OPENEXR_HALF_LIBS@
+synfig_LDADD = ../synfig/libsynfig.la @SYNFIG_LIBS@ @OPENEXR_HALF_LIBS@ @GTHREAD_LIBS@
 synfig_CXXFLAGS = @SYNFIG_CFLAGS@
 #synfig_LDFLAGS=-export-dynamic  -dlopen self
 #-dlopen ../modules/example/libexample.la
diff --git a/synfig-core/trunk/src/tool/main.cpp b/synfig-core/trunk/src/tool/main.cpp
index 77281c8..a5a2c8e 100644
--- a/synfig-core/trunk/src/tool/main.cpp
+++ b/synfig-core/trunk/src/tool/main.cpp
@@ -881,6 +881,9 @@ int main(int argc, char *argv[])
 		return SYNFIGTOOL_BADVERSION;
 	}
 
+	if (!g_thread_supported())
+		Glib::thread_init();
+
 	if(argc==1)
 	{
 		display_help(0);
diff --git a/synfig-studio/trunk/src/gtkmm/app.cpp b/synfig-studio/trunk/src/gtkmm/app.cpp
index 1da982b..b5d4101 100644
--- a/synfig-studio/trunk/src/gtkmm/app.cpp
+++ b/synfig-studio/trunk/src/gtkmm/app.cpp
@@ -1016,16 +1016,16 @@ App::App(int *argc, char ***argv):
 {
 	app_base_path_=etl::dirname(etl::dirname((*argv)[0]));
 
-
-	ui_interface_=new GlobalUIInterface();
-
-	gdk_rgb_init();
-
 	// don't call thread_init() if threads are already initialized
 	// on some machines bonobo_init() initialized threads before we get here
 	if (!g_thread_supported())
 		Glib::thread_init();
 
+	// class UIInterface inherits from etl::shared_object, so we need the thread stuff initialised already
+	ui_interface_=new GlobalUIInterface();
+
+	gdk_rgb_init();
+
 	distance_system=Distance::SYSTEM_UNITS;
 
 	if(mkdir(get_user_app_directory().c_str(),ACCESSPERMS)<0)